Who Audits Public Companies – Spain 2021

The audit market for Bolsa de Madrid listed companies that comprise the three IBEX indices in Spain remains highly concentrated. The 84 companies on the top market cap índices РIBEX 35, IBEX Medium Cap, and IBEX Small Cap Рare all audited by a total of five accounting firms.

Together, the Big Four audit firms account for 99% of engagements on these indices as of fiscal year-end 2021. Marzars held the remaining market share. The addition of Mazars in this market represents a departure from the market share seen in 2020 and 2019.

Among the Big Four, EY audits the most companies comprising these indices, with 32% of the market. KPMG and PwC hold 25% and 23%, respectively. Lastly, Deloitte audits 19% of the companies on these IBEX indices.

2021 Auditor Market Share - Spain


KPMG led the Big Four for audits of IBEX 35 companies in FY 2021, with 14 engagements, overtaking PwC since our last analysis of this market. This year, PwC held nine engagements, representing 26% of the IBEX 35. Deloitte and EY each held 17%, with six engagements each.

KPMG’s market share on this index grew due to auditor rotations and a new constituent member, already audited by the firm, being added to the index.

IBEX Medium Cap

On the IBEX Medium Cap index, EY had the most audit engagements as of FY 2021, auditing nine companies, followed by PwC, who audited six. KPMG and Deloitte audited three and two companies, respectively.

Compared to our 2020 analysis, this represents a vastly different market share of the IBEX Medium Cap. This is due, in part, to the changing constituents on the index and several auditor changes that occurred. Vidrala has joined the index and has engaged EY as its auditor since 2017. Fomento de Construcciones y Contratas and Construcciones y Auxiliar de Ferrocarriles both changed auditors to EY in 2020.

IBEX Small Cap

Of the constituents comprising the IBEX Small Cap index, EY held the most engagements as of FY 2021, auditing twelve companies, followed by Deloitte with eight. PwC and KPMG each audit five.

Mazars audited one company on the index – Artificial Intelligence Structures. The company engaged Mazars as its audit firm in FY 2021, changing from EY in the previous year. While one company is a small slice of the market share, it breaks the grip that the Big Four have held on these indices in the past.

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